Sewing machine



April 23, 1.940. u R, L, LYONS 2,198,312

SEWING MACHINE Filed Jan. '7, 1937 ,20717115 NJ: l

Patented Apr. 23, 1940 SEWING MACHINE Robert L. Lyons, Waltham, Mass.,assigner `to American Button Sewing Machine Co., Waitham, Mass., acorporation of Massachusetts,

'Application January 7, 1937, Serial No. 119,500

10 Claims.

In the operation of sewing machines of the chain stitch type there aremany conditions where diiiiculty has been experienced in properlycontrolling the starting end of the thread so as to avoid long andunsightly loops or free ends projecting from the work. This isparticularly troublesome in connection with machines for attachingarticles such, for example, as buttons, where unsightly loose loops orthread ends commonly protrude from the front faces of the buttons. Thisis particularly liable to occur where the material to which the buttonsare attached is relatively thin and light, as, for example, shirtingmaterial. It has been attempted to positively grip the starting end ofthe thread beneath the work to avoid this trouble, but this has beenliable to leave either a loop on top of the work or a long startingthread end on the back of the work, or if too close adjustment has beenmade in an attempt -to avoid this loop or long thread end, the threadmay be broken, so that the gripper is rendered ineffective to cure thedliculty.

In accordance with the present invention this diihculty from longstarting thread loops or ends is avoided by producing a sufficientfrictional drag on the thread end instead ci?` a positive grip thereon.This so controls the thread end as to avoid the formation of looseloops, and is so directed that any short end which may be left is socaught and held by subsequent stitches as not to be objectionable. Thiscontrolling drag to be effective should be located close to the work,and, because of this, and also for the sake of simplicity, it may beproduced by pressing the thread against the back face of the work. Thismay be done effectively by providing the work table or throat plate withparts against which the work may be pressed, as by the button held bythe button clamp, during the sewing operation.

' For a more complete understanding of this invention, reference may behad to the accompanying drawing in which Figure 1 is a somewhatdiagrammatic side elevation of a button sewing machine embodying thisinvention. l

Figures 2 and 3 are detail sections on lines 2-2 and 3 3, respectively,of Figure 1, Figure 2 being on a larger scale.

Figure 4 is a perspective view of a throat plate.

Figure 5 is a fragmentary perspective view of the forward end portion ofa cloth plate.

Figure 6 is a detail section on line 6--6 of Figure 4.

Figure 7 is a view similar to Figure 6, but showing a modifiedconstruction.

Figure 8 is a view similar to a portion of Figure 2, but to a largerscale and showing the parts after the first stitch has been made.

In Figure 1 is shown a button sewing machine of the type illustrated inmy Patent No. 2,033,080, granted March 3, 1936, for Button sewingmachine, 4though it will be evident, as this descripy tion proceeds,that this invention is applicable to many other types of sewingmachines.

As shown, the sewing machine has a base l 'provided with an upstandingpost 2 from which extends forwardly the usual sewing arm 3 provided witha head 4 at its forward end. Within this head 4 is shown a reciprocatingneedle bar 5 to the lower end of which is secured a sewing needle B ofthewell known type. Cooperating with this needle to form stitches arethe usual loop taking mechanism comprising the rotary looper I and suchother parts as are commonly employed as shown more particularly in myPaten-t No. 2,033,080 hereinbefore mentioned.

The base l carries the usual work table, a portion of which is formed bya throat plate l having a throat Il through which the needle passes toform with the other sewing instrumentalities the stitches which securean article to the cloth. At I is shown a cloth plate of ordinary formhaving an opening I6 therethrough which is substantially larger than thethroat il of the throat plate. This cloth plate l5 is movable relativeto the throat plate, being moved alternately in opposite directions, asdescribed more particularly in my patent hereinbefore noted, so as topresent alternately each of two holes of a pair in the button into theneedle path. Thus in Figure 2 a button to be sewed to the work is shownat 20, this button being held between jaws 2| of a button clamp, whichis mounted for rocking motion laterally and is also liftable to presentthe jaws in convenient position to receive a button to be sewed, and,after the sewing operation, to break the sewing thread, so that thebutton and the work may be readily removed from the machine.

Referring to Figure 2, the button being in place for the start of therst stitching stroke of the needle, the hole 25 in the button ispresented into the needle path. The needle descends through this hole 25and through the work, and the loop of thread is caught by the hook 21 ofthe rotary looper which pulls down the starting end of the thread to aposition beneath the throat plate. After the needle has been lifted fromthis hole 2 amaai:

25, the button clamp is then moved laterally, as shownin Figure 8. sothat the hole 2l in the button is no longer in the needle path but thehole 26 is so presented. This lateral motionof the button, the buttonclamp, and the cloth plate moves the button hole over an extension 3l ofthe throat plate projecting into the opening I6 of the cloth plate sothat the starting thread end 3| is clamped against the lower face of thework by the pressure exerted between the extension and the lower face ofthe button 20. This exerts a frictional drag on the thread end whichholds the thread tight as it is drawn up through the hole 25 of thebutton by the action of the take-up and during the next downward strokeof the needle to present a succeeding loop of thread to be taken by thehook 21 of the looper.-

This holding of the thread end so as to prevent slack between the needleand the upper face oi the button avoids the formation of any loose loopsof thread projecting from the top face of the button. AIi the thread endis so short that it pulls up above the extension 30 so that it is nolonger gripped thereby, it is drawn down by the looper after the nextpass of the needle and gripped between the extension 30a on the oppositeside of the throat Il when the button is snifted back to bring the hole25 into the needle path. Any short ends which may project below thesurface of the work are so positioned by the thread retarding means asto be caught by subsequent stitches and confined and held tight to thework.

The projections 30 and 30a may be formed as by oifsetting the materialof the throat plate on opposite sides of the throat as shown best inFigures 4 and 6, or, if desired they may be formed as oppositelydisposed parts of the head of a sleeve 36, which passes through anopening 31 through the throat plate, and is preferably secured, as byriveting over its lower end 38 against the under face of the throatplate. The central opening 39 of this sleeve forms the throat throughwhich the needle passes.

From the foregoing it will be seen that means have been provided forproducing a frictional drag on the starting thread end which preventsthe formation of loose loops or long thread ends projecting from thefront face of the work, and likewise that the starting end is engagedand sewed into the work by the subsequent stitchlaying operations afterthe rst stitch has been placed. Where this invention is applied to amachine of the type illustrated in my Patent No. 2,033,080, this resultsin the starting thread ends of both sets of stitches, which are placedthrough a four-hole button in a continuous operation, having frictionaldrags exerted successively on the two starting thread ends which aresewed into the work and without the formation of loose starting loops orthread ends projecting from the forward face of the button for eitherset of stitches. The same result is, of course, accomplished where atwo-needle machine is employed as shown in my Patent No. 1,915,829,granted June 27, 1933, except that the frictional drag is exerted at thesame time on both threads.

The projecting portions 30 and 30a, or the head 35, should ordinarilyproject above the remainder of the throat plate by an amountsubstantially equal to the thickness of the cloth plate I5, asordinarily the lower face of the button is substantially in the plane ofthe lower face of the jaws of the button clamp. Thus, as the work ispressed against the top face of the cloth plate by the button clamp. thebutton itself presses the cloth and the starting end of the threadagainst the top face of the cooperating throat plate projection when thebutton has been moved laterally to bring the other hole of a pair intothe needle path, the opening in the cloth plate being so much largerthan the throat that the desired extent of lateral motion of the clothplate -and the button clamp may be made without hindrance from theprojecting portions of the throat plate. By providing a frictional dragfor the starting thread end ot a suillcient amount to give the desiredtension on the thread end between the lower face of the work and theneedle, the thread end may be properly controlled regardless of theparticular length of thread end ,which ordinarily extends from theneedle, so long as there is suiliclent length of thread to prevent theneedle from being Unthreaded when the stitching cycle is commenced.

From the foregoing description of certain embodiments of this invention,it should be evident to those skilled in the art that many changes andmodifications may be made without departlng from the spirit or scope ofthis invention as deiined by the appended claims,

I claim:

1. A machine for sewing articles to work, which comprises sewinginstrumentalitles, work holding means, and means for so relativelymoving said instrumentalities and means during a stitching operation asto sew an article to the work, said machine including means effective bysuch relative motion to position the starting end of the sewing threadto be caught and held to the work by the stitches.

2. A machine for sewing articles to work, which comprises sewinginstrumentalities, work-holding means, and means for so relativelymoving said instrumentalities and means during a stitching operation asto sew an article to the work, said machine including means effective bysuch relative motion to exert a frictional drag on the starting end ofthe thread and to position the starting end of the sewing thread to becaught and held to the work by the stitches.

3. A sewing machine having a work table provided with a throat, a clothplate on said table having an opening therethrough substantially largerthan said throat, means for pressing work against the top face of saidcloth plate, and means adjacent to said throat and extending into saidopening for engaging the lower face of the work and pressing thestarting end of the thread thereagainst.

4. A sewing machine having a Work table, a throat plate carried by saidtable and having a throat, a cloth plate overlying said throat plate andhaving an opening therethrough substantially larger than said throat,said throat plate havlng an extension adjacent to said throat projectingwithin said opening to an extent substantially equal to the thickness 0fsaid cloth plate.

5. A button sewing machine having a throat plate provided with a throat,a cloth plate overlying said throat plate and having an openingtherethrough substantially larger than said throat, and a button clampfor holding a button in position to be sewed to cloth on said clothplate and to hold the cloth against said cloth plate, said throat platehaving an extension adjacent to said throat and projecting within saidopening in position to cooperate with the button held by said clamp to,press the cloth and the l ly larger than said throat, an article carrierfor starting thread end together at the start oi' a button sewingoperation.

6. 'I'he combination with a sewing machine having sewinginstrumentalities including a needle, a throat plate having a throatthrough which said needle passes, a cloth plate above said throat plateand on which cloth may be placed and having an opening therethroughsubstantialholding an article in position to be sewed to the cloth andfor pressing said cloth against said cloth plate, and means forvibrating said article carrier laterally between successive stitchingneedle strokes to present diierent portions of the article alternatelyin position to take stitches, of means at opposite sides of said throatfor pressing the starting end of the sewing thread against the lowerface of the cloth when the article clamp has been vibrated in acorresponding direction at the start of a sewing operation.

7. A sewing machine throat plate having an opening therethrough, and asleeve extending through said opening and provided with a head on itsupper end forming a projection from the top face of said plate aroundthe bore of said sleeve, said bore forming the throat of said plate.

8. A sewing machine throat plate having an opening therethrough. and asleeve extending through said opening and provided with a head on itsupper end forming a projection from the top face of said plate aroundthe bore oi' said sleeve, said bore forming the throat of said plate,said sleeve being headed over against the lower face of said plate.

9. In a button sewing machine having instrumentalities includingstitch-forming elements, work-holding mechanism including a holder for afour hole button, and means for relatively manipulating saidinstrumentalities and mechanism to sew a button held by said holder tothe work by a pair of independent sets of stitches during a singlemachine operation, means exerting a rrlctional drag on the startingthread ends of both sets of stitches.

10. In a button sewing machine having instrumentalities including asingle needle, workholding mechanism including a holder for a four holebutton, and means for relatively manipulating said instrumentalitles andholding mechanism to sew a button held by said holder to the work by apair of independent sets of stitches during a continuous machineoperation, means for successively exerting a frictional drag on thestarting thread ends of both sets of stitches.

